Comment 5 for bug 1763006

gdb-multiarch seemed like it should work.
I use openocd 0.10.0 but when I attempt a connection to it reports of my SAMD09D14A (on an Adafruit Seesaw)
"warning: Architecture rejected target-supplied description
...
Truncated register 16 in remote 'g' packetInfo : dropped 'gdb' connection"

This very helpful post provided the solution and got me here to see what was up:
https://acassis.wordpress.com/2018/12/27/adding-arm-none-eabi-gdb-to-ubuntu-18-04/

gdb-arm-none-eabi works perfectly!